Voice-recognition systems are gradually becoming an effective replacement for keyboards used in computing systems. In a typical voice recognition system, the user installs a voice recognition software, then trains the system to recognize his or her voice. Thereafter, instead of using a keyboard to input commands and/or text to the system, the user speaks into a microphone that is typically worn either as a headset or extends from a pedestal on the user's desk. Current examples of voice-recognition software include IBM's “ViaVoice,” Lernout & Hauspie's “VoiceXpress,” and Dragon System's “Dragon NaturallySpeaking.”
A significant problem encountered in conventional voice recognition systems is the “text-mode/command-mode” problem in which such systems have difficulty knowing whether to interpret the user's words as system commands or insertable text. For example, if while using Microsoft Word the user says “open Web browser,” voice recognition systems have difficulty knowing whether the user wants to open a Web browser as a separate application, or insert text into a Microsoft Word document. Conventional voice recognition systems' solution to this problem is the “command phrase dictionary” by which the system listens for certain exact command phrases which are interpreted as commands rather than text. However, the “command phrase dictionary” approach has several drawbacks. One significant drawback is that it makes the voice recognition system much harder to learn and use. Instead of letting the user use natural language to command the voice recognition system, it requires the user to memorize many command phrases, some of them unnatural, before he or she can use the system effectively. The reason “command phrase dictionaries” must often use unnatural language is that the most obvious phrases may be commonly used in dictated text. For example, some systems require a user to say “scratch that” rather than “delete” in order to delete a phrase, and “microphone off”, rather than “turn the microphone off” or “mike off”, in order to turn off the microphone. Incorrect command phrases will often be interpreted as text for insertion.
Another drawback of the “command phrase dictionary” approach is that, because there is no standard command phrase dictionary among competing voice-recognition system providers, a user must learn multiple command phrase dictionaries if he/she is using different voice recognition systems. Yet another drawback is that the “command phrase dictionary” approach makes the voice recognition system slower. When the voice recognition system hears any word that might be the start of a command phrase, the system must wait to hear the entire phrase before it knows whether or not the user's words are intended as text-mode or command-mode.
It is therefore an object of the present invention to provide a system and method for use in a voice recognition system that will enable the system to know before a user speaks whether the spoken words are to be interpreted as system commands or insertable text. It is also an object of the present invention to provide a system and method that will enable users to issue commands using natural language rather than having to memorize specific command phrases, thereby eliminating the problem of non-standardized “command phrase dictionaries” posed by competing voice recognition systems. Thus, it is an object of the present invention to make voice-recognition systems easier and faster to use than conventional voice-recognition systems.